indication

For the treatment of giardiasis and cutaneous leishmaniasis and the management of malignant effusions.

pharmacology

Quinacrine has been used as an antimalarial drug and as an antibiotic. It is used to treat giardiasis, a protozoal infection of the intestinal tract, and certain types of lupus erythematosus, an inflammatory disease that affects the joints, tendons, and other connective tissues and organs. Quinacrine may be injected into the space surrounding the lungs to prevent reoccurrence of pneumothorax. The exact way in which quinacrine works is unknown. It appears to interfere with the parasite's metabolism.

mechanism of action

The exact mechanism of antiparasitic action is unknown; however, quinacrine binds to deoxyribonucleic acid (DNA) in vitro by intercalation between adjacent base pairs, inhibiting transcription and translation to ribonucleic acid (RNA). Quinacrine does not appear to localize to the nucleus of Giaridia trophozoites, suggesting that DNA binding may not be the primary mechanism of its antimicrobial action. Fluorescence studies using Giardia suggest that the outer membranes may be involved. Quinacrine inhibits succinate oxidation and interferes with electron transport. In addition, by binding to nucleoproteins, quinacrine suppress the lupus erythematous cell factor and acts as a strong inhibitor of cholinesterase.

toxicity

Oral, rat: LD₅₀ = 900 mg/kg; Oral, mouse: LD₅₀ = 1000 mg/kg. Symptoms of overdose include seizures, hypotension, cardiac arrhythmias, and cardiovascular collapse.

absorption

Absorbed rapidly from the gastrointestinal tract following oral administration.

half life

5 to 14 days